Pouch-type packaging is very flexible and adaptable to a variety of medical products, including medical devices. An example of a pouch-type package without formed cavities is two flat similarly sized rectangular sheets of material aligned and placed directly over one another and sealed together along three of their four edges. The fourth edge is left open to form the pouch and provide an entrance opening into the interior of the pouch. The fourth side may be sealed after a product such as a medical device is placed inside the pouch (often referred to the filling process). This operation is not typically conducted in a sterile environment, although it may be. Therefore, it is then desirable to sterilize the product that is now contained within the pouch, along with the interior of the pouch, in order to provide a sterile product. Various types of sterilization processes are known in the art to sterilize medical products, including gas sterilization, autoclaving, gas plasma sterilization, radiation and other conventional processes. When utilizing a gas sterilant process such as ethylene oxide, one of the flat rectangular sheets may include a gas permeable barrier such as a TYVEK® sheet. Sterilization gases can penetrate the gas permeable barrier to sterilize the product inside the sealed pouch. Once the sterilization process is completed, a fifth seal may be made to isolate the product from the gas permeable section of the sealed pouch. Following this operation, the portion of the pouch that contains the gas permeable barrier is removed. When using two sheets which are not gas permeable, the package is sealed along the fourth edge after ethylene oxide sterilization in a clean room.
Forming is defined as the process of creating a cavity in one or both sheets of material used to form the pouch to accommodate a product to be packaged. Formed cavities are especially useful in pouch-type packages because they allow larger products to be housed or filled within a given size pouch without the formation of wrinkles. Wrinkle formation in one or both sheets is typical of a non-formed pouch package. These wrinkles can be eliminated if one or both sheets have pockets formed in them to accommodate the intended product. There may be disadvantages associated with such wrinkles, including channels and unsealed sections or areas which result is a loss of sterility and barrier to moisture and oxygen.
Flat pouches are typically made form roll stock on seal and cut equipment. Pouches may be formed from two rolls of laminate foil material such rolls of heat sealable packaging materials. These materials can be foil laminates, films, heat sealable papers or spun bonded plastics. Thermo forming is performed on films while cold pressure forming is typical for foil laminates Forming process typically are performed on conventional form/fill/seal equipment. These types of systems can easily fabricate numerous flat pouches or envelopes that may be later transported to subsequent operations for filling and final sealing as described above. As previously mentioned, it is often desirable to have a formed cavity in one or both sides of the pouch. This is accomplished by forming a cavity in one (or both) sheet(s), placing the product into a cavity, and then placing and sealing the two sheets together. Where cavities are formed in both sheets, care must be taken to assure accurate registration and alignment of the sheets before they are sealed. This type of process may be automated as a continuous process wherein package formation, filling with product, and sealing are all conducted in a continuous manner. This type of system works well for most products that are not sterile, however, it does not work well for sterile product that needs to be aseptically filled and sealed into the pouch.
Aseptic packaging processes and equipment are known in the art. Aseptically filling and sealing a product into a package is typically conducted in an aseptic environment. Such environments are difficult and costly to fabricate on a scale large enough to accommodate form, fill, and seal systems as described above. One approach used for aseptic packaging is to manufacture pouches in a non-sterile environment, stack them, sterilize them, and then transfer them into an aseptic environment for the filling and sealing operation. This process works well with pouches that are not formed. However, formed pouches present some additional challenges. Formed pouches, when stacked take up much more space and therefore fewer pouches can be accommodated in each stack. Even if gently stacked, the pouches are typically easily damaged during the sterilization process and subsequent transport into an aseptic environment. Damage may include wrinkle formation and hole formation. Wrinkled or unsupported surfaces present yet additional challenges when the application of labels on the outer package surface is desired.
Therefore, there is a need for novel packaging processes and machines for making pouches having formed cavities adapted for use in an aseptic environment.